From 2478510b919e0f8e4284739a5e3cc5eebec1aec3 Mon Sep 17 00:00:00 2001
From: Edwin Kofler <edwin@kofler.dev>
Date: Tue, 27 Dec 2022 05:32:12 -0800
Subject: [PATCH] ci(checkstyle): Add no-pwd-capture test

---
 scripts/checkstyle.py | 43 +++++++++++++++++++++++++++++++++++--------
 1 file changed, 35 insertions(+), 8 deletions(-)

diff --git a/scripts/checkstyle.py b/scripts/checkstyle.py
index c303bc64..35ad8a36 100755
--- a/scripts/checkstyle.py
+++ b/scripts/checkstyle.py
@@ -30,20 +30,34 @@ class c:
     BOLD = '\033[1m'
     UNDERLINE = '\033[4m'
 
+def utilGetStrs(line, m):
+    return (
+        line[0:m.start('match')],
+        line[m.start('match'):m.end('match')],
+        line[m.end('match'):]
+    )
+
 # Before: printf '%s\\n' '^w^'
 # After: printf '%s\n' '^w^'
-def noDoubleBackslashFixer(line: str, rule: Dict[str, str], m: re.Match[str]) -> str:
-    prestr = line[0:m.start('match')]
-    midstr = line[m.start('match'):m.end('match')]
-    poststr = line[m.end('match'):]
+def noDoubleBackslashFixer(line: str, rule: Dict[str, str], m) -> str:
+    prestr, midstr, poststr = utilGetStrs(line, m)
 
-    fixed_line = f'{prestr}{midstr[1:]}{poststr}'
-    return fixed_line
+    return f'{prestr}{midstr[1:]}{poststr}'
+
+# Before: $(pwd)
+# After: $PWD
+def noPwdCapture(line: str, rule: Dict[str, str], m) -> str:
+    prestr, midstr, poststr = utilGetStrs(line, m)
+
+    return f'{prestr}$PWD{poststr}'
 
 def lintfile(filepath: Path, rules: List[Dict[str, str]], options: Dict[str, Any]):
     content_arr = filepath.read_text().split('\n')
 
     for line_i, line in enumerate(content_arr):
+        if 'checkstyle-ignore' in line:
+            continue
+
         for rule in rules:
             m = re.search(rule['regex'], line)
             if m is not None and m.group('match') is not None:
@@ -58,7 +72,7 @@ def lintfile(filepath: Path, rules: List[Dict[str, str]], options: Dict[str, Any
                 print()
 
                 if options['fix']:
-                    content_arr[line_i] = rule['fixer_fn'](line, rule, m)
+                    content_arr[line_i] = rule['fixerFn'](line, rule, m)
 
                 rule['found'] += 1
 
@@ -71,7 +85,7 @@ def main():
             'name': 'no-double-backslash',
             'regex': '".*?(?P<match>\\\\\\\\[abeEfnrtv\'"?xuUc]).*?(?<!\\\\)"',
             'reason': 'Backslashes are only required if followed by a $, `, ", \\, or <newline>',
-            'fixer_fn': noDoubleBackslashFixer,
+            'fixerFn': noDoubleBackslashFixer,
             'testPositiveMatches': [
                 'printf "%s\\\\n" "Hai"',
                 'echo -n "Hello\\\\n"'
@@ -82,6 +96,19 @@ def main():
             ],
             'found': 0
         },
+        {
+            'name': 'no-pwd-capture',
+            'regex': '(?P<match>\\$\\(pwd\\))',
+            'reason': '$PWD is essentially equivalent to $(pwd) without the overhead of a subshell',
+            'fixerFn': noPwdCapture,
+            'testPositiveMatches': [
+                '$(pwd)'
+            ],
+            'testNegativeMatches': [
+                '$PWD'
+            ],
+            'found': 0
+        },
     ]
 
     parser = argparse.ArgumentParser()